// Copyright (c) 2017 Franka Emika GmbH
// Use of this source code is governed by the Apache-2.0 license, see LICENSE
#include <cmath>
#include <iostream>

#include <franka/exception.h>
#include <franka/robot.h>

#include "examples_common.h"

/**
 * @example generate_joint_velocity_motion.cpp
 * An example showing how to generate a joint velocity motion.
 * 展示关节速度运动发生器
 *
 * @warning Before executing this example, make sure there is enough space in front of the robot.
 */

int main(int argc, char** argv) {
    if (argc != 2) {
        std::cerr << "Usage: " << argv[0] << " <robot-hostname>" << std::endl;
        return -1;
    }
    try {
        franka::Robot robot(argv[1]);
        setDefaultBehavior(robot);

        // 将机器人复位
        std::array<double, 7> q_goal = {{0, -M_PI_4, 0, -3 * M_PI_4, 0, M_PI_2, M_PI_4}};
        MotionGenerator motion_generator(0.5, q_goal);
        std::cout << "WARNING: This example will move the robot! "
                << "Please make sure to have the user stop button at hand!" << std::endl
                << "Press Enter to continue..." << std::endl;
        std::cin.ignore();
        robot.control(motion_generator);
        std::cout << "Finished moving to initial joint configuration." << std::endl;

        // Set additional parameters always before the control loop, NEVER in the control loop!
        // Set collision behavior.
        robot.setCollisionBehavior(
            {{20.0, 20.0, 18.0, 18.0, 16.0, 14.0, 12.0}}, {{20.0, 20.0, 18.0, 18.0, 16.0, 14.0, 12.0}},
            {{20.0, 20.0, 18.0, 18.0, 16.0, 14.0, 12.0}}, {{20.0, 20.0, 18.0, 18.0, 16.0, 14.0, 12.0}},
            {{20.0, 20.0, 20.0, 25.0, 25.0, 25.0}}, {{20.0, 20.0, 20.0, 25.0, 25.0, 25.0}},
            {{20.0, 20.0, 20.0, 25.0, 25.0, 25.0}}, {{20.0, 20.0, 20.0, 25.0, 25.0, 25.0}});

        double time_max = 1.0;  // 三角函数周期
        double omega_max = 1.0;  // 最大角速度
        double time = 0.0;
        robot.control(
            [=, &time](const franka::RobotState&, franka::Duration period) -> franka::JointVelocities {
                time += period.toSec();
                // 周期时长为 time_max, 偶数周期为 1, 奇数周期为 -1
                double cycle = std::floor(std::pow(-1.0, (time - std::fmod(time, time_max)) / time_max));
                // 角速度, 偶数周期 0 -> omega_max -> 0, 奇数周期 0 -> -omega_max -> 0
                double omega = cycle * omega_max / 2.0 * (1.0 - std::cos(2.0 * M_PI / time_max * time));

                franka::JointVelocities velocities = {{0.0, 0.0, 0.0, omega, omega, omega, omega}};

                if (time >= 2 * time_max) {  // 两个周期后结束
                    std::cout << std::endl << "Finished motion, shutting down example" << std::endl;
                    return franka::MotionFinished(velocities);
                }
                return velocities;
            });
    } catch (const franka::Exception& e) {
        std::cout << e.what() << std::endl;
        return -1;
    }

    return 0;
}
